Volkswagen's bullet-shaped L1 concept car at the Frankfurt motor show is more than just an attempt to grab the miles-per-gallon headlines - much of it could go into production.
Although its tandem seating layout and waist-high body will not see the light of day, its hybrid powertrain and carbonfibre-reinforced plastic construction will.
One insider told us that they have officially passed from the 'research' stage to 'development', which means the company intends to use them.
Dr Ulrich Hackenberg, head of VW research and development, said: 'The L1 is a technology carrier. We are using it to develop new technologies for later introduction.'
The car is powered by an 800cc two-cylinder turbodiesel engine developing 27bhp in Eco mode or 29bhp in Sport. It also has a 14bhp electric motor that engages when extra acceleration is needed or for driving the car for short distances in town.
VW claims average fuel consumption of 205mpg, with C02 emissions of 36g/km less than half those of the new Polo Bluemotion.
One possible outlet for the powertrain is the new small car, code-named Up!, that VW is developing for introduction in 2011-12.
The fourth concept in the Up! family also appears at the Frankfurt show, but this time with the front-wheel-drive layout it will have when it goes on sale. The body also looks close to production-ready and features sports styling similar to the latest Golf and Polo.
The show car, badged E-Up!, is an all-electric model powered by an 80bhp motor and a lithium-ion battery pack
housed beneath the floor. VW claims a range of 80 miles on a full charge. Solar panels on the roof aid recharging.
Dr Hackenberg says an electric Up! is also a production possibility if demand is there. 'They make sense for city areas, particularly if there are tax advantages for buying them,' he added.
He believes there is still the potential for a great deal of development with the company's direct-injection petrol and diesel engines to lower fuel consumption and CO2.
Engine capacities will continue to get smaller, with turbochargers making up for the performance deficits, and electronics will control things such as oil and water pumps that are now driven off the engine.
V6 and V8 engines will be reserved for so-called premium cars. 'It is easier for VW to abandon V engines than for Audi,' he said.